Thermal device for heat generating source

ABSTRACT

A thermal device for cooling a heat generating source is provided, including a first portion and a second portion which is formed from the first portion, the area of the bottom of the second portion is smaller than the area of the bottom of the first portion, and the area of the bottom of the second portion accords with a contact surface area of the heat generating source.

FIELD OF THE INVENTION

The present invention relates to thermal devices, and particularly to a thermal device for dissipating heat from or cooling off a heat generating source.

DESCRIPTION OF RELATED ART

Computers may not work properly when the temperature of their central processing units (CPUs) rises above 64° C. To prevent overheating of a CPU a thermal device is often attached to the CPU for heat dissipation.

FIG. 4 shows one of a currently used thermal device 1, including a base 12, a plurality of parallel fins 14, and two heat pipes 16. The base 12 is a slab-shaped metal block with a rectangular bottom. Two holes are defined in the base 12. The fins 14 extend up from the base 12. Two pairs of holes are respectively defined in the base 12 and the fins 14 for receiving the heat pipes 16 therein. The base 12 is coupled to a CPU. The area of the base 12 is larger than that of the CPU. However, manufacturing the thermal device 1 requires comparatively more metal raw material, which adds greatly to the cost of manufacture.

What is needed, therefore, is a lower cost thermal device which still provides good heat sink performance.

SUMMARY OF THE INVENTION

A thermal device for dissipating heat from a heat generating source is provided. The thermal device includes a first portion, and a second portion formed on the bottom of the first portion. An area of a bottom of the second portion is smaller than an area of a bottom of the first portion, and the area of the bottom of the second portion accords with an area of a contacting surface of the heat generating source.

Other advantages and novel features will be drawn from the following detailed description of a preferred embodiment with attached drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a thermal device, in accordance with a preferred embodiment of the present invention;

FIG. 2 is a front view of FIG. 1 without the heat pipes;

FIG. 3 is a side view of FIG. 1 with a motherboard thereunder; and

FIG. 4 is an isometric view of a conventional thermal device.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a thermal device 2 in accordance with a preferred embodiment of the present invention, including a base 22, a plurality of parallel fins 24, and two heat pipes 26 is shown.

As shown in FIG. 1 and FIG. 2, the base 22 includes a first portion 222 and a second portion 224. The first portion 222 is generally rectangular-shaped. The second portion 224 is generally square shaped, and protrudes from a middle of a bottom of the first portion 222. The dimensions of the second portion 224 are less than that of the first portion 222. Therefore, the base 22 has a cross section that is wide at the top and narrow at the bottom. An area of the bottom of the second portion 224 is the same as a top contacting surface area of a heat generating source, such as a CPU used as an example in the preferred embodiment. Two parallel, arc shaped holes 226 a are defined in the first portion 222 from one end of the first portion 222 to near another end of the base 22. And two arc-shaped parallel holes 226 b are defined in the second portion 224 aligned with the holes 226 a. The holes 226 a, 226 b cooperate to receive ends of the heat pipes 26.

As shown in FIG. 2 and FIG. 3, the fins 24 extend up from a top surface of the first portion 222 perpendicular to the base 22. Each fin 24 is a slim rectangular-shaped metal piece with two circular holes 242 symmetrically defined near a top edge thereof. The two holes 242 are for receiving other ends of the two heat pipes 26.

Referring to FIG. 1, the generally U-shaped heat pipes 26 are inserted into the holes 226 of the base 22 and the holes 242 of the fins 24. Heat in the base 22 will be conducted to the fins 24 by the heat pipes 26 to accelerate the process of dissipating heat from the chip.

As shown in FIG. 3, in use, the thermal device 2 is fixed on a chip 50 of a motherboard 70. The second portion 224 of the base 22 contacts the chip 50. Heat produced by the chip 50 is conducted to the second portion 224, and then to the first portion 222. Thereafter, the heat is conducted to the fins 24 through the heat pipes 26, so that the chip 50 can be kept at acceptable working temperatures.

In comparing the conventional thermal device 1 of FIG. 4 with the thermal device 2 in accordance with the preferred embodiment of the present invention of FIG. 1, it can be seen that a volume of the material used for manufacturing the base 22 of the thermal device 2 is less than the volume of material used for the conventional thermal device 1. Thereby there is a reduction in cost of manufacture.

In comparing the conventional thermal device 1 with the thermal device 2 of the preferred embodiment under same testing conditions, (ambient temperature of 35° C., rotation speed of a cooling fan 3800 round/min, BTX style layout) we have the results: Testing Thermal device 1 Thermal device 2 Temperature component temperature (° C.) temperature (° C.) required (° C.) CPU 63.26 63.61 <64.1 Sound card 43.32 43.69 <100 Video card 67.52 67.3 <85 Clock chips 54.81 56.87 <85

It is evident that the cooling performance of the thermal device 2 of the preferred embodiment is comparable to the thermal device 1.

It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of a preferred embodiments, together with details of the structure and function of the preferred embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A thermal device for a heat generating package, comprising: a plurality of fins; and a base having a first portion and a second portion, the first portion supporting the plurality of fins, and the second portion formed from a bottom of the first portion, the area of a contacting surface of the second portion being less than that of the bottom of the first portion, and according with that of a contacting surface of the heat generating package.
 2. The thermal device as claimed in claim 1, further comprising at least a heat pipe extending from the base to the fins.
 3. The thermal device as claimed in claim 2, wherein a portion of the heat pipe is exposed where the second portion does not cover the bottom of the first portion.
 4. The thermal device as claimed in claim 2, wherein a hole is defined in the base for receiving the heat pipe, a top longitudinal portion of the hole is defined in the first portion, and a bottom longitudinal portion of the hole is defined in the second portion.
 5. The thermal device as claimed in claim 1, wherein both the first portion and the second portion are slab-shaped metal blocks.
 6. The thermal device as claimed in claim 1, wherein the second portion protrudes from the first portion.
 7. The thermal device as claimed in claim 2, wherein the heat pipe is U-shaped.
 8. A thermal device for cooling a heat generating source comprising: a base with a cross section having a top dimension wider than a bottom dimension, the area of a contacting surface of the base according with a contacting surface of the heat generating source; a plurality of fins extending from the base, and at least a heat pipe extending from the base to the fins.
 9. The thermal device as claimed in claim 8, wherein the base includes a slab-shaped first portion and a slab-shaped second portion, the area of bottom of the second portion being smaller than the area of the bottom of the first portion.
 10. The thermal device as claimed in claim 12, wherein a hole is defined in the base for receiving the heat pipe, a top longitudinal portion of the hole is defined in the first portion, and a bottom longitudinal portion of the hole is defined in the second portion.
 11. The thermal device as claimed in claim 8, wherein the second portion protrudes from the first portion.
 12. The thermal device as claimed in claim 8, wherein the heat pipe is U-shaped. 